Continuous mixer



April 7, 1964 w. M. MADsEN CONTINUOUS MIXER 5 Sheets-Sheet 1 Filed Aug. 29, 1960 w, Mm M f 6 M April 7, 1964 w. M. MADsEN CONTINUOUS MIXER 5 Sheets-Sheet 2 Filed Aug. 29, 1960 April 7, 1964 1` w. M. MADsl-:N 3,128,085

CONTINUOUS MIXER Filed Aug. 29, 1960 5 Sheets-Sheet 3 M/a//cr M. Maa/sen,

INVENTOR.

by y

United States Patent C) poration of Pennsylvania Filed Ang. 29, 1965, Ser. No. 52,641 d Claims. (Si. 259-169) This invention relates generally to mixing apparatus for mixing various materials and relates more particularly to continuous mixing apparatus for such materials.

While the invention has particular utility in conneetion with apparatus for mixing paving materials and the like, and is shown and described in such connection, it Vis to be understood that .its utility is not conned thereto.

The provision of apparatus which will continuously mix such material and discharge same in a continuous flow presents certain problems and difliculties, and it is an object of the present invention to provide apparatus which will solve said problems and overcome said difiiculties.

It is another object of the invention to provide apparatus of this character having means to improve mixing conditions.

Still another object of the invention is to provide apparatus of this character having means to put the material in the mixer under pressure to thereby densify the mix therein.

A further object of the invention is to provide apparatus of this character having adjustable means to variably control the pressure to which the mass of material in the mixer is subjected.

A further object of the invention is to provide apparatus wherein there is means for raising or lowering the head or height of material within the mixer.

Another object of the invention is to provide apparatus of this character which will discharge the material in a continuous flow.

Still another object of the invention is to provide apparatus of this character wherein said apparatus has improved discharge means and characteristics.

A further object of the invention is to provide apparatus of this character having a compartmented discharge area or region, there being means setting olf this area or region from the rest of the interior of the mixer.

A still further object of the invention is to provide apparatus of this character wherein the size of the compartment, region or area is adjustable or variable.

Another object of the invention is to provide apparatus of this character wherein there are means for working the material toward the discharge end and forcing said material into the discharge compartment.

Still another object of the invention is to provide apparatus of this character having means for creating pressure within the mixer at a location intermediate the ends of the mixer to thereby improve the mixing action.

A further object of the invention is to provide apparatus of this character having a maximum of installation flexibility to meet the needs of the site upon which it is to be operated.

Another object of the invention is to provide apparatus of this character that is relatively simple in construction.

Still another object of the invention is to provide apparatus of this character that is relatively simple and reliable in operation.

Another object of the invention is to provide apparatus of this character that is durable.

The characteristics and advantages of the invention are further suiiiciently referred to in connection with the following detailed description of the accompanying drawings, which represent one embodiment. After consider- 3,128,685 Patented Apr. 7, 1964 ICC ing this example, skilled persons will understand that many variations may be made Without departing from the principles disclosed, and I contemplate the employment of any structures, arrangements or modes of operation that are properly within the scope of the appended claims.

Referring to the drawings, which are for illustrative purposes only;

FIG. 1 is a side elevation of continuous mixing apparatus embodying the present invention;

FIG. 2 is a top plan view thereof;

FIG. 3 is a sectional view taken on line 3-3 of FIG. 2;

FIG. 4 is a sectional view taken on line 4 4 of FIG. 2;

FIG. 5 is an enlarged fragmentary View of the discharge end of the mixer with portions broken away;

FIG. 6 is a sectional view taken on line 6 6 of FIG. 1; and

FIG. 7 is a fragmentary top plan view of the discharge compartment.

Referring more particularly to the drawings, there is shown support means, indicated generally at 10, for the apparatus, said support means including a frame 11 of channel members, or the like, supported by press-broke leg columns'12 having sufcient strength to support the frame 11 and the apparatus mounted thereon. Braces 14, welded or otherwise suitably secured to the frame 11 and respective legs 12 add rigidity to the support means 10. Each leg is provided at its lower end with a foot plate 15.

The legs 12 are of such height as to space the frame 11 a suicient distancerabove the ground or other surface upon which the mechanism or apparatus is disposed so that trucks to be loaded with the mixed material may pass under said frame 11. Also, the spacing of the legs from each other is such as to permit drive-through passageways therebetween for said trucks. On the frame 11 there is secured a supporting means, indicated generally at 20, and comprisinga frame 21 of suitable channel or other members attached to the frame 11. Above the frame 21 there is a larger frame 22 which is also of channel members, or the like. Frames 21 and 22 are connected together by vertical or upright members 23 which support frame 22 in upwardly spaced relation to frame 21. There are also bracing members, indicated at 24, and bracing plates 25 for strengthennig the supporting means 20.

Within the supporting means 20 there is the usual mixed material receiving hopper 30 fwhich is secured within the support means 20 in any well known manner. Hopper 30 is provided with the usual double, clam shell type discharge gates for controlling the ydischarge of mixed material into dump trucks. Since the discharge control gates for the mixed material receiving hopper are well known, said gates are not shown. However, it is to be understood that the opening and closing of said gates is effected by any suitable Well known means, such as pneumatic actuators, or the like.

The mixing apparatus is mounted on the frame 22 of the support means 20, there being a frame 35 attached to the frame 22 by any suitable well known means, such as bolts or the like.

The present mixing apparatus comprises a mixer, indicated generally at 36, said mixer being of the twinshaft pug mill type. Mixer 36 comprises a hollow body 37 which forms a pair of mixing chambers within which parallel shafts 38 and 39 are rotatably mounted.

Shafts 38 and 39 are each provided with a plurality of mixing paddle assemblies, indicated generally` at 40, said paddle assemblies including arms `41 secured to the shafts 38 and 39 in the usual well known manner. At their free ends the arms are provided with the usual paddles or blades `42.

It is to be noted that the paddles on shaft 38 are all inclined in one direction, except at lthe left hand end, as viewed in FIG. 2. The latter paddles, indicated at 43, are oppositely inclined. Shaft 38 is rotated in a direction which will cause the paddles 42 thereof to Work the material in the mixer body 37 leftwardly, as viewed in FIG. l, toward the paddle assembly having the paddles 43. The latter paddles will move the material transversely in the mixer body toward the adjacent paddle assembly f the shaft 39'.

The paddles '42 of shaft 39 are all similarly inclined with respect to the direction of rotation of shaft 39' except for fthe paddles of the two paddle assemblies adjacent the leftward end of shaft 39: Paddles of said end assemblies are indicated at 45 and are parallel to the axis of shaft 39. Paddles '45, which will be termed the discharge actuators or paddles, mo-ve material from the area in which they operate transversely of the mixer and into area 46', which may be termed the discharge area of the mill.

The bottom of the mixer body has a `discharge opening 47 in lthat portion of the mixer body beneath the discharge area 46, and the eiective size of this discharge opening is controlled by a sliding gate 4S, which provides adjustable means for controlling the size of the opening 47.

Gate 48 is slidably supported on rollers 49 which extend longitudinally relative to the body 37 of the mixer, said gate being held laterally in alignment with the opening 47 by guide members `50, PIG. 5, said gate having spacers 51 on the sides thereof which slidably engage the sides Sil when said gate is moved in the opening or closing direction. The end of the gate `48 which is movable under the opening 47 is provided with a plate 54 on the top thereof, which is exposed to the interior of the mixer body through said opening. At the opposite end of the gate there -is an end member 5 which extends transversely of the gate and is provided with a threaded opening 57 for threadable reception of a screw 58. The latter has an end portion 59 which projects outwardly of the adjacent channel member 60 of the frame 35. The screw 58 has a head 61 at the outer end thereof which may be square or otherwise formed for reception of an actuating tool. Screw `61 is also provided with a flange `612 which is disposed between the inner side of the frame member 60 and a retainer member 63 secured to the frame member 60 so that the screw is held' against longitudinal movement and rotation of said screw will effect opening or closing movement `of the gate `48* to thereby vary the effective size of the discharge opening through which material in the body 37 is discharged.

There is also another `discharge opening for the mixer, said discharge opening being indicated at 65 and being controlled by a gate 66 which has its upper end I67 secured by any suitable means, such as welding or the like, to a horizontal shaft 68 which is rotatably mounted in openings provided therefor in frame members 69 and 70 of the mixer.

At one end of shaft `68 there is attached thereto one end of a lever 71, said lever extending downwardly and having its opposite end pivotally secured by a pin 72 to the outer end of a rod 73 which extends into a cylinder 74 and is slidably movable relative to said cylinder. The inner end of the rod is provided with a spring retainer 75 against which the inner end of a spring 76 reacts, the opposite end of said spring reacting against a plate 77 closing the end of the cylinder adjacent the lever 71. The end of cylinder y'74 opposite lthe lever 71 is provided with an eye 78 for reception of a hook end 79 of an adjustment rod 80, the opposite end of said rod 80l extending through an opening provided therefor in aauge 81 of the mixer, the end port-ion of said rod `80 which extends through said flange 81 being threaded, as at 82, and provided with an adjustment nut 83 and a lock nut 84. With this arrangement the tension of spring 76 may be adjustably varied and the rod Si) locked in adjusted position.

'4 By varying the eifective force of the spring 76 the force urging the gate 166 closed is varied.

With the gate -arrangement above described, it will be apparent that there is a slid'able gate which may be iniinitely adjusted from its closed position -to a wide open position, and a hinged gate which is spring loaded and has a tension arrangement which is adjustable. It is to be noted that the tension of any spring within the cylinder 74 may be adjusted by the rod `80. Another means for providing a different closing force for the gate 66 is the changing of the size of the spring in the cylinder 74.

Thus, the mixer has two discharge openings. There is the opening 47 controlled by the sliding gate 48, which is adjustable to vary the volume of discharge through said opening 47. Gate 48 controls the normal flow through the plate at a volume capacity of the larger part of the mixer output. For example, the discharge through the opening 47 may be approximately 75 percent of the mixer output. The gate 66 moves rhythmically under the eifect of pressure exerted by the mix which, when momentarily past, enable the gate to close until the pressure buildup in the mixer again cause said gate to open. The purpose of this arrangement is to densify the mix within the mixer. By controlling the outgo through a iixed opening in combination with the opening controlled by the hinged, spring-loaded gate, the operator is provided with the facilities necessary to provide a very satisfactory mix. Since the resistance which can be created upon the mass of material mixing in the continuous mixer is adjustable in volume of discharge, the density can be varied as desired by varying the yielding force on the gate 66, urging said gate in the closing direction.

The mixer is also provided with a partitioning device or means at the discharge end for setting off the area 46 into a discharge compartment. This partitioning means comprises a pair of laterally spaced plates 86 and 87, which have their outer and lower edges secured to adjacent portions of the adjacent side wall and bottom wall of the mixer body by any suitable means, such as welding or the like.

The inner edges 90 and 91 of the plates 86 and 87 are curved with a substantial portion thereof on a radius based on the axis of the adjacent shaft 38. Within the space 92 between the plates 86 and 87 there is slidably disposed a movable partition 94 having its inner edges curved similarly to the curvature of the inner edges of the plates 86 and S7. An outer end portion of movable partition 94 extends outwardly of the adjacent wall of the body through a slot 94a in said wall of the body. At the outer end ofthe partition there is an anvil 95 for striking with a suitable Sledge-hammer, or the like, to loosen the partition, if cemented up and stuck, and drive same inwardly. The outer end portion of partition 94 also is provided with irregularly shaped openings 96 for reception of a pinch bar, not shown, which is fulcrumed on a block, also not shown, for moving the partition outwardly. Thus the effective size of the partitioning means for the discharge area is adjustable. Of course other adjusting means also may be used. In FIG. 4 the movable partition 94 is shown at its inward limit of movement and it is movable outwardly to a position whereat its inner curved edge 93 is in substantially the same plane as the edges 90 and 91 of the partitions 36 and 87.

Intermediate the ends of the mixer body and at the side opposite the discharge area there is another adjust able partition means, indicated generally at 100, FIG. 1. This partition means includes a movable partition or plate 101, which is slidably disposed between guides 102 and 103 at opposite sides thereof, said guides having their outer and lower edges suitably secured to the adjacent portions of the adjacent side wall and the bottom of the mixer body. There is a plunger 104 which has its inner end secured to the plate 101 by any suitable means, such as welding, and which extends outwardly through an opening provided therefor in the adjacent side wall of the mixer body. A knob 105 is also provided at the outer end of plunger 104 so that adjustments of the partition or plate 101 will be easier.

The mechanism is provided with a receiving hopper 108 for the aggregate, such as crushed rock of various sizes from approximately l/z-inches down to stone dust, said hopper being disposed at the end of the body opposite the discharge end and being supplied with material by means of a conveyor belt 109 of the usual well known character.

Means for operating the apparatus comprises a power means 112 which may be an internal combustion engine, electric motor, or the like, which is mounted on a part of the supporting frame at one side of the mixer body. A belt 114 connects the power means 112 with a shaft 116 which is connected to a gear mechanism 117 by means of a coupling 113. The gear mechanism 117 actuates the shafts 38 and 39 in opposite directions, as is the usual practice. Water is supplied to the apparatus by means of a water pump 119 which is connected to a suitable source of water supply and said pump delivers water to the interior of the mixer body by means of a conduit 120, shutoff 121, conduit 122, automatic water volume control unit 123, conduit 124, and water distribution manifold 125, which has spray nozzles, or the like, which discharge water into the mixer body in the usual well known manner.

Material in the mixer body is moved from the end receiving aggregate and the like toward the discharge end. The movement of the material is effected primarily by the paddles 42 of the shafts 38 and 39. When the material moved by the paddles 42 of the shaft 38 reach the partition means at the inner end of the discharge area and the paddles 43, said material is moved laterally by said paddles 43 so that the last set of paddles 42 of the shaft 39 will move the material into the area wherein paddles 45 operate and the latter paddles will move the material into the discharge area 46, where it will be discharged through the openings 47 and 65.

The partition means, including the plates 86 and 87, and the partition 94, stop the movement of the material longitudinally of the mixer body toward the outlet com partment or area, and provides resistance to the movement of said material. This partition means, working in conjunction with the slidable gate 48 and the hinged gate 66, creates such resistance to the movement of the material within the mixer as to densify or pressurize the material.

The provision of the discharge opening at one side of the mixer body, and at the discharge end, has been found to improve results, and by having the compartmentization of the discharge area there is a forced right angle ejection of material within this compartment.

The utilization of the intermediate adjustable partitioning means 100 aids in further densiiication or pressurizing of the aggregate within the mixer during the mixing process.

The invention and many of lits attendant advantages will be understood `from the foregoing description and it will be apparent that various changes may be made in the form, construction and arrangement of the parts of the invention without departing from the spirit and scope thereof or sacrificing its material advantages, the embodiment hereinbefore described being merely for purposes of illustration.

I claim:

1. A continuous mix plant, comprising: a twin-shaft pug mill mixer body including bottom, end and side walls, said body having a discharge opening in the bottom -wall and side wall at one end and at one side off the longitudinal center thereof; a pair of parallel, laterally spaced, longitudinally extend-ing shafts rotatably mounted in said body; inwardly and outwardly adjustable laterally arranged partition means adjacent said discharge opening at the side thereof yopposite the -adjacent end wall of the body, to thereby defi-ne a discharge compartment opening laterally toward the opposite side of said body; sets of .6 paddles operably attached to the shafts and spaced apart longitudinally relative to said shafts, a set of paddles on one shaft located adjacent the partition means, the paddles on said one shaft, except for the set of paddles adjacent the partition means, being inclined to move material in the body toward said partition means, the set of paddles adjacent said partition means being oppositeiy inclined to cause the material in said body to be moved transversely thereof to the opposite side of the mixer body, the other shaft having sets of paddles arranged generally opposite the paddles of the one shaft and inclined to move material in the body toward the discharge end thereof, said other shaft having two sets of paddles opposite the open end of the discharge compartment arranged with their faces parallel ot the axis of the mixer shaft upon which they are mounted and being adapted to move material laterally into .the discharge compartment; la slidable gate adjustably mounted to vary the size of the discharge opening in the bottom of the mixer body; a second gate controlling the side discharge opening and pivoted at its upper edge for swinging movement on a horizontal axis; yielding means yieldingly urging the second gate toward the closed position; means for adjustably varying the force of the yielding means on said second gate; and second inwardly and outwardly adjustable partition means within the body upstream of the discharge opening, and at the opposite side of the body from said discharge opening.

2. A continuons mix plant; comprising: a twinfshaft pug mill mixer body including bottom, end and side walls, said body having a discharge opening in .the bottom wall and side wall at one end and at one side of the longitudinal center thereof; a pair of parallel, laterally spaced, longitudinally extending shafts rotatably mounted in said body; inwardly and outwardly adjustable partition means adjacent said discharge opening and at the side thereof opposite the adjacent end wall of the Ibody, to thereby define a discharge compartment opening laterally toward the opposite side of said body; sets of paddles operably attached to the shafts and spaced apart longitudinally relative to said shafts, a set of paddles on one shaft located adjacent the partition means', the paddles on said one shaft, except fo-r the set orf paddles adjacent the partition means, being inclined to move material in the body toward said partition means, the set of paddles adjacent said partition means being oppositely inclined to cause the material in said body to be moved transversely thereof to the opposite side off the mixer body, the other shaft having sets of paddles arranged generally opposite the paddles of the one shaft and inclined to move material in the body toward the discharge end there-of, said other shaft having two sets of paddles opposite the open end of the discharge compartment arran ed with their faces parallel to the axis of the mixer shaft upon which they are mounted and being adapted to move material laterally into the discharge compartment; a slidable gate adjustably mounted to vary the size of the discharge opening in the bottom of the mixer body; a second gate controlling the -side discharge opening and pivoted at its upper edge for swinging movement on a horizontal axis; yielding means yieldingly urging the second gate toward the closed position; and means for adjustably varying the force of the yielding means on said second gate.

3. In a continuous mix plant: a twin-shaft pug mill mixer body including bottom, end and side walls, said body having a discharge opening at one end and at one side of the longitudinal center thereof, said opening having a bottom part and a side part; a pair of parallel, laterally spaced, longitudinally extending shafts rotatably mounted in said body; laterally arranged partition means adjacent said discharge opening and at the side thereof opposite the adjacent end wall of the body to thereby define a discharge compartment opening laterally inwardly of said body; means operably attached to the shafts for moving material in said body toward the disy7 Y charge end thereof; means on one shaft adjacent the partition means for moving material in said body transversely toward the other shaft; means on said other shaft and adjacent the open side of the discharge compartment for moving material laterally into said discharge compartment; a gate adjustably mounted to vary the size of the bottom part of the discharge opening; a pivoted gate controlling the side part of the discharge opening;

.yielding means yieldingly urging said pivoted gate to the closed position; and second laterally arranged partition means within the body upstream of the discharge opening and at the side of the body opposite said openmg.

4. In a continuous mix plant: a twin-shaft pug mill mixer body including bottom, end and side Walls, said body having a discharge opening at one end and at one side of the longitudinal center thereof; a pair of parallel, laterally spaced, longitudinally extending shafts rotatably mounted in said body; partition means adjacent said discharge opening and defining with the adjacent end Wall of the body, a discharge compartment opening laterally inwardly of said body; means operably attached to the shafts for moving material in said body toward the discharge end thereof; means on one shaft adjacent the partition means for moving material in said body transversely toward the other side of said body; means on said other shaft and adjacent the open side of the discharge compartment for moving material laterally into said discharge compartment; a pivoted gate controlling the size of a part of the discharge opening; and yielding means yieldingly urging said gate toward the closed position.

References Cited in the le of this patent UNITED STATES PATENTS 616,373 Upton Dec. 20, 1898 1,401,052 Danks Dec. 20, 1921 1,948,871 Quehl Feb. 2,7, 1934 1,971,632 Anderson Aug. 29, 1934 2,757,912 Madsen Aug. 7, 1956 .FOREIGN PATENTS 18,163 Great `Britain 1901 275,789 Switzerland Sept. 1, 1951 838,443 Germany May 7, 1952 

4. IN A CONTINUOUS MIX PLANT: A TWIN-SHAFT PUG MILL MIXER BODY INCLUDING BOTTOM, END AND SIDE WALLS, SAID BODY HAVING A DISCHARGE OPEIING AT ONE END AND AT ONE SIDE OF THE LONGITUDINAL CNETER THEREOF; A PAIR OF PARALLEL, LATERALLY SPACED, LONGITUDINALLY EXTENDING SHAFTS ROTATABLY MOUNTED IN SAID BODY; PARTITION MEANS ADJACENT SAID DISCHARGE OPENING AND DEFINING WITH THE ADJACENT END WALL OF THE BODY, A DISCHARGE COMPARTMENT OPENING LATERALLY INWARDLY OF SAID BODY; MEANS OPERABLY ATTACHED TO THE SHAFTS FOR MOVING MATERIAL IN SAID BODY TOWARD THE DISCHARGE END THEREOF; MEANS ON ONE SHAFT ADJACENT THE PARTITION MEANS FOR MOVING MATERIAL IN SAID BODY TRANSVERSELY TOWARD THE OTHER SIDE OF SAID BODY; MEANS ON SAID OTHER SHAFT AND ADJACENT THE OPEN SIDE OF THE DISCHARGE COMPARTMENT FOR MOVING MATERIAL LATERALLY INTO SAID DISCHARGE COMPARTMENT; A PIVOTED GATE CONTROLLING THE SIZE OF A PART OF THE DISCHARGE OPENING; AND YIELDING MEANS YIELDINGLY URGING SAID GATE TOWARD THE CLOSED POSITION. 